glance configuration options in docs

I am installing and configuring glance in a CentOS 7 VM, following the official guide http://docs.openstack.org/liberty/install-guide-rdo/glance-install.html. It suggests the following configuration in /etc/glance/glance-api.conf:

The auth_uri/auth_url pattern looks rather bizarre to me. Thus I referred to the http://docs.openstack.org/liberty/config-reference/content/ch_configuring-openstack-image-service.html (configuration reference), and it has identity_uri instead. Do they function in the same way? auth_url is described as a registry configuration option, in the DEFAULT section, which should be in /etc/glance/glance-registry.conf I suppose? Furthermore, there are admin_user, admin_password, admin_tenant_name etc., but username, password, project_domain_id and others are not found in the reference. Which document is correct, or both are? Why?